1. Field of Invention
This invention relates to an agricultural implement for planting seed and injecting dry fertilizer (dry granular material) while at the same time tilling the soil.
2. Discussion of Prior Art
Historically in agriculture, planting the crop has been a separate operation from the tillage operation which is used to kill unwanted weeds and grasses. For many years (since the late 1800's), there have been attempts to try to combine the tilling operation with the planting operation but these attempts have never really caught on. Several reasons for this lack of success has been: 1) the tilling operation does not provide a good seedbed for the seed or 2) the equipment to do this has been costly, requiring completely new implements.
Currently, seed boots are being manufactured which attach to a chisel shank, in which a small sweep shovel is also attached. U.S. Pat. No. 5,033,398 currently covers such a seed boot and manufacturers such as Flexi-Coil and John Deere manufacture similar boots. This type of configuration does accomplishes the objective of getting the seed and/or fertilizer in the ground while at the same time tilling the soil. Unfortunately, the seed is placed on firm, compacted soil, called a sweep layer, and is subsequently covered up by loose soil then followed by a presswheel to firm the soil above the seed. This sweep layer is not an ideal seedbed because the roots are inhibited from establishing themselves downward through the sweep layer. Also, with the loose soil left on top and/or adjacent to the seed, the adjacent soil usually dries out beside the seed which in turn attracts moisture away from the seed instead of directing moisture towards the seed. Needless to say, this type of planting operation is inferior to planting the seed inside a narrow groove with loose sidewalls adjacent to the seed similar to most seed boots that do not combine the tilling operation.
In 1987, another type of implement was patented (U.S. Pat. No. 4,770,112), in which the planting and tilling operations seemed to be adequately combined. The design has a narrow point extending vertically lower than the wings of a sweep shovel in which a narrow groove is formed and then followed behind by the sweep shovel in order to undercut the adjacent soil killing any unwanted grasses or weeds. This invention has some major pitfalls. It is a unique invention that does not attach to any other implements except to the implement as part of the invention and it does not use any other standard, commercially available sweep shovels. Therefore, the farmer must purchase costly new equipment instead of using standard equipment they may already have. The Deere and Company invention also directs the seed sideways which places the seed on the top of the sweep layer instead of into the narrow groove. The groove is formed for the placement of fertilizer below and away from the seed so that more fertilizer can be injected into the soil during this operation than could be done otherwise if the seed and fertilizer were placed (banded) together.
Relatively narrow knives have also been used in agriculture for forming a narrow groove in the soil in which liquid or gaseous fertilizer is injected into the ground. Usually, there is a separate implement that only has knives attached to it and is not suited for tilling the ground at the same. In 1979, an invention, U.S. Pat. No. 4,141,301, was designed to both fertilize and till at the same time but it does not appear suited for planting and does not use commercially available sweep shovels.